A new high-performance AC/DC power factor correction switching converter based on one-cycle control technology and active floating-charge technology

A new family of converters, high-performance AC/DC power factor correction （PFC） switching converters with onecycle control technology and active floating-charge technology, was derived and experimentally verified. The topology of a single-phase CCM and DCM Boost-PFC switching converter was also analyzed. Its operating prniciples and control methods were expounded. Based on these, a new type of AC/DC switching converter circuits for PFC combined with one-cycle control technology was presented herein. The proposed AC/DC switching converter significantly helps improve the converter efficiency and its power factor value.     

Crashing from cadaver to computer: Covid-driven crisis-mode pedagogy spawns active online substitute for teaching gross anatomy

In early 2020, the Covid-19 crisis forced medical institutions worldwide to convert quickly to online platforms for content delivery. Although many components of medical education were adaptable to that format, anatomical dissection laboratory lost substantial content in that conversion, including features of active student participation, three-dimensional spatial relationships of structures, and the perception of texture, variation, and scale. The present study aimed to develop and assess online anatomy laboratory sessions that sought to preserve benefits of the dissection experience for first-year medical students. The online teaching package was based on a novel form of active videography that emulates eye movement patterns that occur during processes of visual identification, scene analysis, and learning. Using this video-image library of dissected materials, content was presented through asynchronous narrated laboratory demonstrations and synchronous/active video conference sessions and included a novel, video-based assessment tool. Data were obtained using summative assessments and a final course evaluation. Test scores for the online practical examination were significantly improved over those for previous in-person dissection-based examinations, as evidenced by several measures of performance (Mean: 2015–2019: 82.5%; 2020: 94.9%; P = 0.003). Concurrently, didactic test scores were slightly, but not significantly, improved (Mean: 2015–2019: 88.0%; 2020: 89.9%). Student evaluations of online sessions and overall course were highly positive. Results indicated that this innovative online teaching package can provide an effective alternative when in-person dissection laboratory is unavailable. Although this approach consumed considerable faculty time for video editing, further development will include video conference breakout rooms to emulate dissection small-group teamwork.     

基于文本编辑方式下的ASP脚本调试技巧

基于ASP技术WEB应用系统的开发正在广泛流行,而大量的初学者面临着如何在文本编辑方式下对脚本程序的编写与调试问题。通过ASP中脚本程序常见错误进行分析,并且指出相应的代码编写及调试技巧,为ASP开发的初学人员提供捷径。     

串/并联级联混合型有源电力滤波器APF控制技术和电路拓扑结构研究

并联有源电力滤波器是一种用于动态抑制谐波和补偿无功的新型电力电子装置,近年来,有源电力滤波器的理论研究和应用均取得了较大的成功。对其主电路（VSI）参数的设计也进行了许多探讨,APF的作用是用电压型或电流型逆变器产生一个“注入”电网的谐波电流,以抵消其它装置有网侧产生和谐波电流,进而净化电网侧的电压和电流波形。通过分析有源电力滤波器的交流侧滤波电路对电流补偿性能的影响,在满足一定效率的条件下,对有源电力滤波器电路进行了仿真分析研究。     

增强英语课堂学生的主体参与意识

被动的接受对于学生的英语学习是没有多大益处的，本文论述了几种教学方法来增强学生的主体参与意识，激励学生的学习兴趣，最终达到提高学习效率的目的。     

更新观念做好读者服务工作

高校图书馆工作必须具备的基本要求是牢固树立“读第一,服务至上”的服务宗旨,为了适应这一要求,图书馆工作人员不仅要有扎实过硬的专业知识和相关知识,而且要有热情、周到的服务意识,变被动为主动。     

基于B/S的高校教务管理无纸化办公系统

分析了教务管理系统的发展趋势及其特点,定义了系统的功能,应用模块化设计思想将这些功能需求划归为基础信息、教务管理、信息查询等功能模块.介绍了基于B/S模式的教务管理系统的设计思想,详细设计了每个模块的主要功能.它的开发及应用提供了灵活、方便的管理机制,实现了教务管理的无纸化.     

积极自信的课堂教学氛围的营造策略

在化学教学中,由于教师过多的批评,灌输式的教学方式,不健康的心理场效应,以及学生自信心不足、被动的学习习惯而导致课堂氛围消极、沉闷。教师应从新课的引入、积极鼓励、提供舞台、加强暗示、满足好奇心等方面采取相应的策略,建立以学生为主体的积极、自信的课堂教学氛围。     

An Active Reading Model for English Learners

Acuve reading makes a reader interact with the text.It promotes learning,Acuve reading model actually presents six reading strategies that teachers should consider when teaching English to a class of non-native speakers.That guides both teachers and students in their working and learning.     

对“教师是主导,学生是主体”命题的多学科视角的审视

"教师是主导,学生是主体"这一说法在我国教育理论界和实践界流行甚广,然而,当把这一命题置于哲学的、教育学的、逻辑学的多学科视角的理性拷问后,不难发现这一看似科学的、进步的"教育公理"却存在着诸多的谬误。错误的教育理论必然误导教育实践的发展,要正确认识教师与学生在教学过程中的地位与作用,就必须祛弊归正。